Morphometric and Technological Analysis of Acheulean Large Cutting Tools From

1 Morphometric and technological analysis of Acheulean Large Cutting Tools from 2 Porzuna (Ciudad Real, Spain) and questions of African affinities 3 4 Adrián Arroyo1, 2*, Tomos Proffitt3*, Alastair Key4* 5 1 Institut Català de Paleoecologia Humana i Evolució Social (IPHES), Zona Educacional 4, Campus Sescelades 6 URV (Edifici W3) 43007, Tarragona (Spain) 7 2 Universitat Rovira i Virgili (URV), Àrea de Prehistòria, Avinguda de Catalunya 35, 43002 Tarragona, Spain 8 3 Institute of Archaeology, University College London, 31–34 Gordon Square, London WC1H 0PY (UK) 9 4 School of Anthropology and Conservation, University of Kent, Canterbury, Kent CT2 7NR (UK) 10 11 *Corresponding authors: [email protected] (A. Arroyo); [email protected] (T. Proffitt) 12 [email protected] (A. Key) 13 14 Abstract 15 The Acheulean of central Spain is well known from a handful of sites. Rarely, however, are 16 these assemblages subject to systematic technological and morphological analyses. Numerous 17 years of surface collection within the Porzuna area (Ciudad Real) has yielded a substantial 18 collection of Lower-Middle Palaeolithic lithic material (with over 8000 stone tools), now 19 housed at the Museo Provincial of Ciudad Real. It has been suggested that the LCT technology 20 of the Spanish Acheulean may have been directly influenced by ESA African technological 21 traditions; however, others have suggested a European origin for the technology. Here we 22 present a techno-typological and 3D morphometric analysis of the LCT’s collected at Porzuna. 23 We compare the Porzuna artefacts to other known local assemblages from Ciudad Real as well 24 as Acheulean LCT’s from north, east and South Africa, to investigate potential technological 25 and morphological affinities. Results of our analysis show that despite sharing technological 26 similarities, such as the use of large flakes as blanks, significant morphological differences 27 exist between the African and Iberian LCTs. 1 28 Keywords: Large Flake Acheulean; Iberian Peninsula; handaxe; morphometric analysis; Early 29 Stone Age 30 31 1) Introduction 32 33 The Acheulean emerged in East Africa in association with a new species, Homo erectus 34 s.l., and became the longest lasting human cultural tradition (~1.76-0.2 million-years-ago 35 [Mya]). Characterised by the appearance of large flake technologies and bifacially flaked core 36 tools (Isaac, 1969; de la Torre et al., 2008), collectively termed as large cutting tools (LCTs), 37 the rapid diffusion of Acheulean technology between 1.76 and 1.7 Mya is evidenced at sites 38 such as Kokiselei 4 at West Turkana (Kenya) (Lepre et al., 2011), KGA6-A1 at Konso 39 (Ethiopia) (Beyene et al., 2013), FLK W at Olduvai Gorge (Tanzania) (Diez-Martín et al., 40 2015), and Gona (Quade et al, 2004; Semaw et al., 2018). Subsequently, Acheulean LCT’s 41 became widespread across Africa, Europe, the Levant and large swathes of Asia and Arabia 42 (e.g. Isaac, 1977; de la Torre et al., 2008; Presnyakova et al., 2018; Mishra et al, 2010; Goren- 43 Inbar and Saragusti, 1996; Zhang et al., 2010; Shipton et al., 2014; 2018). 44 The origin and dispersal of the Acheulean in Europe is an important and ongoing point 45 of debate. This includes within the Iberian Peninsula, where the earliest evidence of hominin 46 occupation comes from sites such as Barranco León and Fuente Nueva, dated to 1.4-1.2 Ma 47 (Toro Moyano et al., 2011), and Sima del Elefante (Atapuerca) (Carbonell et al., 2008) dated 48 to 1.2 Ma; although their lithic assemblages have been classified as Oldowan or Mode 1. The 49 earliest Iberian Acheulean assemblages have been documented at Barranc de la Boella, dated 50 to ca. 1 Ma (Valverdú et al., 2014), and Cueva Negra, dated to 0.9-0.78 Ma (Scott and Gibert, 51 2009). Middle Pleistocene sites are, however, common on river terraces across the Iberian 52 Peninsula. This includes the central Spanish area of Porzuna and Campo de Calatrava, where 2 53 several Acheulean sites have previously been identified along the Guadiana River and its 54 tributaries (Santonja and Redondo, 1973; Santonja and Querol, 1976; Vallespí et al. 1979; 55 1980; Alañón Flox 1980; 1982; Ciudad Serrano et al., 1983a; Ciudad Serrano, 1986). Other 56 large river basins in the Iberian Peninsula with documented Acheulean sites include the Tagus 57 and its tributaries (Santonja et al., 1978; Querol and Santonja, 1979; Santonja and Pérez- 58 González, 2002; Rodríguez de Tembleque et al. 2004; Santonja and Villa, 2006), and the 59 Guadalquivir river basin (Vallespí, 1992; Caro Gómez, 2000; Fernández Caro, 2008) (Figure 60 1). The wide documentation of LCTs across the Iberian Peninsula has resulted in multiple 61 analyses highlighting their importance to hominin populations in this region (Santonja and 62 Villa, 1990; 2006; Arroyo and de la Torre, 2013; Méndez-Quintas et al, 2018). 63 64 Figure 1. Location of a selection of Middle Pleistocene Acheulean sites from the Iberian 65 Peninsula. Legend: 1. Budiño; 2. Porto Maior; 3. Galería (Atapuerca); 4. Puig d’Esclats; 66 5. La Cansaladeta; 6. Torralba and Ambrona; 7. La Maya; 8. San Isidro; 9. Áridos; 10. 67 Pinedo; 11. Puente Pino; 12. El Sartalejo; 13. Gruta da Aroeira; 14. Santa Ana; 15 68 Porzuna; 16. El Sotillo; 17. Albalá; 18. El Chiquero; 19. Las Jarillas. 3 69 The earliest hominin migrations into Iberia, and in turn the appearance of the 70 Acheulean, could have occurred through two routes. Individuals could either have colonised 71 the peninsular from a North Africa route across the Strait of Gibraltar or spread through 72 Western Europe. To date, both remain viable as potential dispersal routes of Acheulean 73 technology into Iberia. Archaeological and faunal evidence has led O’Regan (2008) and 74 Martínez and Garriga (2016), for example, to favour repeated episodes of Acheulean hominin 75 population dispersals from Western European and the Levant into Iberia. Alternatively, Sharon 76 (2011) has suggested a North African dispersal, based on the use of large flakes for biface 77 manufacture, the high number of cleavers in assemblages, and the use of raw materials beside 78 flint. To date, however, few studies have set out to formally test the hypothesised north African- 79 Iberian dispersal routes as evidenced through lithic artefacts. Indeed, in a similar vein to 80 hominin dispersal studies in other regions, there is a need for detailed typo-technological and 81 morphometric comparisons of artefacts from both ‘origin’ and ‘destination’ localities (Goren- 82 Inbar and Saragusti, 1996; Lycett and von Cramon-Taubedel, 2008; Lycett, 2009; Fleagle et 83 al., 2010; Shipton and Petraglia, 2011; Wang et al., 2012). 84 Here, we present a technological and 3D shape analysis of a new Acheulean LCT 85 assemblage collected from the Porzuna area of Ciudad Real, Spain. Our aim is to conduct a 86 comparison of LCTs from this location with six other known Acheulean assemblages from 87 Campo de Calatrava (El Sotillo and El Chiquero, Spain), north Africa (STIC and Cunnette), 88 East Africa (HK, Olduvai Gorge) and South Africa (Elandsfontein). We assess techno- 89 typological and 3D morphometric traits from Porzuna alongside these Spanish and African 90 assemblages, contextualizing the Porzuna artefacts among other Central Spanish sites, while 91 also contributing to our understanding of potential south-western dispersal routes into Europe 92 by Middle Pleistocene hominins. 93 4 94 2) Materials and Methods 95 96 2.1 Materials 97 The archaeological locality of Porzuna 98 Porzuna lies in the north-west of Ciudad Real province (Spain), close to the foothills of 99 the Montes de Toledo (in the north) and the volcanic area of Campo de Calatrava (to the south). 100 Porzuna valley is crossed by the Bullaque River and filled with alluvial fan deposits. Multiple 101 open-air artefact localities occur on its +5m river terrace. Our recent visits to the area confirmed 102 the availability of high densities of raw material (mainly quartzite) and artefacts (Figure 2). 103 104 Figure 2. Location of Porzuna and general view of the area. Black squares refer to the points 105 where lithics where collected (according to Vallespí et al., 1985). 5 106 The Porzuna assemblage currently contains over 8000 artefacts (including cores, 107 débitage, retouched pieces and LCTs [bifaces, cleavers, picks and large flakes]) recovered by 108 various prospectors from the 1950s onwards. First reported by Vallespí and colleagues (1979 109 and 1985), the assemblage was initially considered a mixture of Acheulean and Mousterian of 110 Acheulean Tradition (MTA) artefacts, with very high densities of bifaces (>400), cleavers 111 (>300) and picks (>130). Such occurrences were rarely documented outside of Africa at that 112 time. Despite the lack of radiometric dates, Ciudad Serrano (1988) estimated the site to be 113 included within the last glaciation (Würm I; ca 115 Kya). In a wider regional context, additional 114 studies of the Guadiana and Jabalón rivers documented the presence of the Acheulean 115 assemblages in +10/13 m and +8 m terraces (Santonja, 1996; Santonja, Pérez González, 2002, 116 2010), while the only radiometric chronology available to date was obtained from a +13/16 m 117 terrace in the Guadiana river dated to 153.867 BP (López et al., 2005). 118 The lithic collection presented in this paper belongs to a previously unreported Porzuna 119 assemblage deposited at the ‘Museo Provincial of Ciudad Real’ in 2015. Collected by a local 120 prospector and subsequently donated, it consists of 216 artefacts separated into two localities: 121 Las Casas del Rio (n= 58, 27%) and the larger assemblage of Las Tinosillas (n= 157, 73%) 122 (Table 1). Within this assemblage there is a clear bias towards larger artefacts (cores and LCTs) 123 compared to debitage which is underrepresented in the analysed assemblage.

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